Outboard heating device

ABSTRACT

In a nebulizer an assembly for continuously heating water drawn from a reservoir to a nebulizing chamber comprises a hollow spool for directing water from the reservoir to a heating chamber, an exterior jacket spaced from the spool to provide a heating chamber and a heater surrounding at least a portion of the jacket.

' Unlted States Patent 1 1 1 3,859,398 Havstad 6 1451 'Jan. 7, 1975 [5 1OUTBOARD HEATING DEVICE 2,040,630 5/1936 Silten 128/193 x 3,584,9656/1971 Chztstanier.... 219/273 X 175] f R-Hav5md- Lakewood 3,683,1538/1972 Heyer 219/275 C 3,695,516 10/1972 Rogers 219/275 x 1 1} AssigneeHudson Oxygen Therapy Sa FOREIGN PATENTS o'R APPLICATIONS CompanyTemecula 680,195 2/1964 Canada.,.., 219/273 [22] Filed: Oct. 5, 1972634.758 2/1962 Italy 219/273 [2]] Appl' 295]56 Prim a ry ExaminerTim R.Miles t Assistant Exizminer+Richard LQChiesa "152] U.S. 261/14],128/193,'219/275, Attorney, Agent, or Firm-Jerry R. Seiler 26l/D1Gf65{51] Int. Cl. B0lf 3/04, A6lm 15/00 [57] ABSTRACT [58] Field0i.Search....;.- 261/78A, 141-142, I I

261mm. I88 I92 111 a nebullzer an assembly for continuously heatmg219/271 water drawn from EITBSEIVOII' to a nebullzmgchamber I 4comprises a hollow spool for directing water from the 5 Reference; Citedreservoir to a heating chamber, an exterior jacket spaced from the spoolto provide a heating chamber STATES PATENTS I and a heater surroundingat least a portion of the 451,822 5/1891 Henry 128/192 j k t v 1,554,2199/1925 Kitchen 128/l93X 2,005,229

6/1935 Loos et a]. 219/275 X 3 Claims, 5 Drawing Figures PATENTEUJANH915 3.859.398

SHEET 2 OF 2 1 OUTBOARD HEATING DEVICE BACKGROUND OF THE INVENTION Mistor aerosol producing devices often referred to as nebulizers arecommonly used for the treatment of respiratory ailments and aregenerally considered important for inhalation therapy. Nebulizersgenerate a fine mist or aerosol of wateror aqueous medicament mixturesto yield a high humidity aerosol which is particularly effective fortreatment of asthma, pneumonia, bronchitis, enphysema and the like. Onesuch nebulizer, which also functions alternately as a humidifier, isdisclosed in co-pending application Ser. No. 45,192 filed June 10, 1970.

For certain patients and in the treatment of a number of respiratoryailments or diseases, it is preferred to have the water or aqueousmedicament solution to be nebulized, heated rather than administeredcold or at ambient temperature. Heated aerosols are preferred sinceinspired gases close to body temperatures are less irritating ondelicate membranes in the patients nasal and throat areas as well as inthe lungs. Particularly, for patients suffering from asthma orpneumonia, inspiration of cold or even relatively cool air should beavoided to prevent irritation, discomfort as well as undue loss of bodyheat. Heating of the water also heats the gas to be inhaled and whichheated air can hold more moisture thereby achieving a higher humidity.

Heating of-watei' or aqueous solutions to be administered in an aerosolnebulizer is often carried out by the use of immersion-type heatingdevices. Such heaters are usually of the tube type and contain heatingelements enclosed in an outer jacket. The heater tube is immersed withinthe liquid holding reservoir containing water or aqueous medicamentsolution which become heated by direct contact with'the jacket. Such aheating method may not be satisfactory since contamination of the wateror medicament may result from contact with the immersed heater.

Another heater type comprises a blanket heater which contacts only theexterior of the nebulizer liquid holding chamber. Although thecontamination problem is thus eliminated instead heat must betransferred through the nebulizer wall. If the walls are made ofplastic, unless it is of a high heat resistant type, there is the dangerof deforming the plastic, or even causing it to melt which of course isquite objectionable and may defeat the purpose and/or efficiency of thedevice.

Either of the above-mentioned methods of heating the water is quite timeconsuming since the whole volume of water present in the nebulizer mustbe heated to the temperature desired. Obviously, where the nebulizer isto be used on an as needed basis, having to wait for all of the water'toheat before the device can be utilized for therapy is in most casesunacceptable. Moreover, the use of blanket heaters, especially forplastic nebulizer jars is even more time consuming since the heat mustbe transferred through the plastic jar thereby lowering the heatingefficiency and causing additional time delay.

Heaters for nebulizers, andespecially of the disposable nebulizers arepreferably removable for reuse and to allow an operator or therapist theoption of installing a heater if desired. The heater should also be onethat preferably does not cause contamination of the water or solution tobe nebulized for patient inspiration, is preferably inexpensive,relatively simple to operate and one which can be readily adapted toavailable nebulizers without requiring their extensive redesign.

SUMMARY OF THE INVENTION It is to the elimination of the problems notedhereinabove as well as to achieve the objects specified that the presentinvention is directed.

The heating concept and device of the invention involves passing streamof water or aqueous solution to be nebulized through a heatingcompartment, exterior to the nebulizer or liquid holding reservoir as itis drawn to a nebulizing chamber.

The device consists of an assembly having a passageway systemcommunicating with the nebulizer liquid holding reservoir and nebulizertube and comprises an inner conduit for directing a liquid stream fromthe reservoir to a heating chamber, an exterior jacket enclosing theinner conduit but spaced apart therefrom to provide a liquid directingchanneland heating chamber therebetween, and a heater around theexterior jacket for providing heat therethrough to the heating chamher.

The device is inexpensively manufactured, easy to use and install, evenby inexperienced personnel, and is readily adaptable-to present types ofnebulizers including disposable humidifier-nebulizers of the type forexample disclosed in US. application Ser. No. 45,192 filed June 10,1970. These as well as other advantages will be more evident in view ofthe following detailed description.

BRIEF DESCRIPTION or THE DRAWINGS FIG. 1 is a side sectional elevationshowing assembled components of the assembly of the invention;

FIG. 2 is a sectional elevation of another assembly embodiment;

FIG. 3 is a perspective view of the spool of the assemy;

FIG. 4 is a view of a bushing and cap, the former for installing theassembly components of the device and the latter for closing thepassagewayv system when the heater device is not to be used; and

FIG. 5 is 'a side sectional elevation of another embodiment of theheating assembly of the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, thedevice of the invention is shown secured to a nebulizer jar adjacent aliquid holding reservoir. More specifically, in the nebulizer jar 44,liquid holding reservoir 40 is defined within the jar. Extendingvertically along the nebulizer jar is tube 28 for directing water oraqueous medicament solution from reservoir 40 to a nebulizing chamber(not shown). Normally, as will be appreciated by those skilled in theart, the nebulizer. will function by the Venturi principal whereby astream of air is passed into a nebulizing chamber creating a partialvacuum or low pressure within the chamber. Tube 28 is in communicationwith the low pressure nebulizing chamber so that a continuous column ofliquid in tube 28 will be drawn or siphoned upwardly into the chamberfrom reservoir 40. Tube 28 is generally circular in crosssectionalthough its shape is not particularly critical.

Tee fitting 21 extends from jar 44 and provides a cavity 35 whichcommunicates with both tube 28 and reservoir 40. Tee fitting 21 'has aninboard or inwardly extending portion 23 and an outboard or outwardlyexisnot-critical so long as components of the outboard heater assemblycan be secured thereto.

The outboard heater assembly of the invention consists'of a hollow spool18, an exterior jacket 20, bushing 24 and heater 25. Spool 18incorporates a hollow interior which providesa conduit 22 through whichliquid travels between inlet port 37 and outlet port 39. Spool 18 isalso provided with radially extending end flange 48 which provides forsealing engagement with the interior surface of inboardportion 23 of teefitting 21.

Sealing engagement of those components is important -so that unheatedcool water or solution passing through the heater'device from reservoir40 must pass first through inlet port 37 and thereafter is directedthrough the'assembly rather than passing directly into tube 28 r byleakage between flange 48 and inboard portion 23.

' ing engagement between spool 18 and inboard portion of tee fitting 21may be used. For example, referring to FIG. 2, inboard portion 23a maybe provided with collar 41 against which flange 48 of the spool may besealingly engaged. For'this purpose, it may also be advisable toincorporate a washer 43 or gasket or O-ring'so as to' further ensureagainst liquid leaking between the collar and flange. Othersimilar andequivalent methods of sealingly engaging these components may also beutilized within the purview of the invention.

Referring again to FIG. 1, spool 18 includes an outwardly or radiallyprojecting collar 31 which collar includes multiple orifices 32 (notealso FIG. 3). At the forward end of the spool is a liquid'outlet port39. An

exterior jacket having a rear seating flange 27 covers spool 18 as shownand is spaced therefrom to provide channel '16 between these twocomponents.

A collar 31 extends radially from the spool surface with a plurality oforifices 32 as shown so'that water or aqueoussolution may flow fromforward outlet port 39 along channel vl6 toward tube 28 as it is' drawnup-.

" itsouter surface and jacket 20.

Bushing 24 secures the components to tee fitting 21 and is provided withinterior threads 23 for threadedly engaging outboard portion 26 of teefitting 21. With exwater is also drawn from reservoir 40 into inletport' 37 of, the spool. A multi orificed cover 34 is shown which acts asa screen or filter to prevent large particles from entering thenebulizer passageways although such a cover is entirely optional. Theunheated liquid passes from inlet port 37 toward outlet port 39 throughconduit 22. Forwardly disposed from outlet port 39 and along theremaining exterior surface of spool 18 adjacent spaced jacket 20 is theheating chamber 14. Heater body 25 which is maintained at any desiredtemperature for required heating of the water passing through theheating chamber, substantially contacts the exterior of jacket 20 andwhichheat is then transferred through the jacket wall into theheatingchamber. Thus, cool water arrives at outlet port 39 andthereafter becomes heated by being exposed to thewarm interior surfaceof jacket 20. This heated water or aqueous medicament is then drawnalong channel 16 toward tube 28 through orifices 32 and into tube 28 'tobe nebulized chamber. The heater may be of a fixed temperature or may bevariable as desired. It will be appreciated that some heat' may passthrough spool 18 so 'that'liquid passing along conduit 22 will besomewhat heated before reaching port 39. l-loweven where the spool isterior jacket 20 in place, seating flange 27 and collar 31 becomeengaged as bushing 24 is tightened so as to provide a liquid tight sealtherebetween when the device is in operation. For this purpose, O-rings,gaskets, washers or the like may be installed orincorporated betweenengaging portions of the bushing, jacket rear flange 27, and spoolcollar 31.

Referring to FIG. 1, the heating assembly device of the inventionoperates as follows:

. With the components in place, as water or aqueous medicament solutionisdrawn upwardly through tube 28 into a nebulizing chamber as previouslyexplained,

made of a plastic or synthetic resin material, heat transfer through-thewalls will not be extremely significant,

good heat transfer quality. Aluminum or similar lightweight andrelatively inexpensive metalis preferred. More effective liquid heatingmay be accomplished by reducing the distance across conduit 22 so thatthe volume of liquid in the conduit at any time will be reduced. It willbe evident that where the amount of water passing through the conduit isless, itjwill be heated to a higher temperature than a larger amount ofwater, assuming the same flow velocity and heating temperature. I jReferring to FIG. 5, there is shown an alternativeembodiment ofa spool48 having a modified means of sealing engagement with nebulizerpassageway components. More specifically, the spool shown includes aninlet port 47 and outlet port 49, collar 57 and orifices 61 quitesimilar to equivalent partsof the spool shown in FIG. 1. The nebulizer,a portion of which is shown, is altered somewhat from that shown in FIG.1 so that the passageway system from the reservoir 62 includes lowertube52 and upper tube 50, the lower tube being in communication with thereservoir and the upper tube extending toward and communicating with anebulizing chamber (notshown); The end portion 51 of the spool 48extends into L-shaped or elbow fitting 54 which directs the water oraqueous medicamentsolution from lower tube 52 into the heating apparatusassembly. As shown, L-shaped fitting 54 is tapered and narrows inwardlyso that the end 51 of the spool can be maintained in sealing engagementtherewith. Accordingly, as the spool is urged inwardly against theinterior sure against seepage or leakage of cool water from the interiorof the assembly with the warm water side.

The jacket shown includes a sheath portion 60 through which heat istransferred and which interiorly I defines the heating chamber betweenits inner surface and spaced exterior surface of spool 48 in a mannerdescribed in FIG. 1. The jacket also includes a threaded end member 64which threadedly engages outwardly extending threaded connecting portion56 of a nebulizer jar. Spool end 51 will be urged into tapered portion54 as jacket bushing member 64 is further engaged and urges spool collar57 inwardly (from left to right). The engagement of jacket bushingmember, spool collar and threaded connecting portion. provides a liquidtight sealbetween these abutting component portions. The components areassembled by first inserting spool end 51 into engagement with L-shapedmember 54 of a nebulizer passageway system and thereafter simplythreadedly engaging the jacket portion 24 until the components arefirmly in place.

The device shown in FIG. 5 operates quite similar to that shown anddiscussed hereinabove regarding FIG. 1. Water or aqueous medicamentsolution will be drawn upwardly from reservoir 62 through lower tube52', into inlet port 47, through conduit 45, through outlet port 49 andinto heating chamber 65. Heat transferred from heater body 25 throughjacket 60 will increase the water temperature passing through theheating chamber and the heated water will then pass along channel 66,through orifices 61 and finally through upper tube 50 to be nebulizedfor patient inspiration.

When heating of the water or solution to be nebulized is no longerdesired, the assembly can be simply removed by disengaging bushing 24(FIG. 1) or jacket 60 (FIG. 5) and removing the jacket and spool.Thereafter, a cap 68, shown in FIG. 4, may be threadedly engaged to thethreaded outwardly extendingnebulizer portion to close off the portafter the removal of the assembly components. The nebulizer will thenfunction normally without heating. It will be evident that the assemblydescribed offers a most efficient and simple means of heating water oraqueous medicament solutions to be delivered to a patient without therequirement of heating the entire body of water or solution in thenebulizer jar reservoir or its contamination by inserting heatingelements or components. Except for the heat transferring jacketpreviously described and the heater itself, the assembly components maybe molded plastic such as polyethylene, polystyrene and styrenecontaining copolymers and terpolymers for example, ABS plastics, etc.Especially useful are polyphenylene oxides such as NORYL resins becauseof their high temperature characteristics. Accordingly, the device maybe relatively inexpensive so that all components except for the heatermay be disposable thereby eliminating possible contamination of othernebulizers.

I claim:

1. In a nebulizer having a tube for drawing liquid from a reservoir to anebulizing chamber, an improved heater assembly comprising: a

a. an inner conduit comprising a hollow spool having an inlet portadjacent said reservoir and an outlet port communicating with a heatingchamber,

b. an exterior jacket spaced apart from said inner conduit whereby saidjacket and conduit cooperate to define said heating chambertherebetween,

c. means communicating'with said reservoir for directing liquidtherefrom to said conduit inlet port, and

d. a heater surrounding at least a portion of said jacket for providingheat thereto, whereby liquid is drawn from said nebulizer reservoir,through said conduit and into said heating chamber prior to nebulizationin said nebulizing chamber.

2. The assembly of claim 1 including a channel between said heatingchamber and said nebulizer tube and communicating therewith fordirecting heated liquid from said heating chamber to said tube.

3. The assembly of claim 2 wherein said nebulizer includes a cavitybetween said reservoir and said tube and wherein said spool extends intosaid cavity and is in sealing engagement therewith whereby liquid mustpass successively through said conduit, heating chamber and channelprior to being drawn into said nebulizer tube.

1. In a nebulizer having a tube for drawing liquid from a reservoir to anebulizing chamber, an improved heater assembly comprising: a. an innerconduit comprising a hollow spool having an inlet port adjacent saidreservoir and an outlet port communicating with a heating chamber, b. anexterior jacket spaced apart from said inner conduit whereby said jacketand conduit cooperate to define said heating chamber therebetween, c.means communicating with said reservoir for directing liquid therefromto said conduit inlet port, and d. a heater surrounding at least aportion of said jacket for providing heat thereto, whereby liquid isdrawn from said nebulizer reservoir, through said conduit and into saidheating chamber prior to nebulization in said nebulizing chamber.
 2. Theassembly of claim 1 including a channel between said heating chamber andsaid nebulizer tube and communicating therewith for directing heatedliquid from said heating chamber to said tube.
 3. The assembly of claim2 wherein said nebulizer includes a cavity between said reservoir andsaid tube and wherein said spool extends into said cavity and is insealing engagement therewith whereby liquid must pass successivelythrough said conduit, heating chamber and channel prior to being drawninto said nebulizer tube.